linux/drivers/xen/xen-balloon.c
Linus Torvalds d4c6fa73fe Features:
- PV multiconsole support, so that there can be hvc1, hvc2, etc;
  - P-state and C-state power management driver that uploads said
    power management data to the hypervisor. It also inhibits cpufreq
    scaling drivers to load so that only the hypervisor can make power
    management decisions - fixing a weird perf bug.
  - Function Level Reset (FLR) support in the Xen PCI backend.
 Fixes:
  - Kconfig dependencies for Xen PV keyboard and video
  - Compile warnings and constify fixes
  - Change over to use percpu_xxx instead of this_cpu_xxx
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQEcBAABAgAGBQJPZ0qkAAoJEFjIrFwIi8fJjCgH/jeJ39E8ML8DP9tCS2HQnMqM
 uTEjLcqvoJ7sEhHvtBLPeG2p0jyBvOWjLbSc7P8nESBAMPvSYol8L6WqfWrdSU4r
 lHrma2sg9UYzRog5NyxAgkp7bBsBBFOnhVL3Cxb5Ig78cPWzeSWGpqGZ8M/d51Wf
 1iE0tHuU4DpN+fg1SZqPqEm8ecEJ/eSrVTnyTx/Qo2Ak+Zw98SqzX7SV5lo8mudd
 WFL1F2K9FyTNk79ndGhqFt36x6nEbFgMLbmCDWumLuWN6bMd1Uq0wNkCqW4F1h28
 3yqnY+rfQh4y3eXK1B9nttCUTs+/66U5ZWrT6B1IJumGTAIqcWfgeUX/Vn/HVC4=
 =tfMc
 -----END PGP SIGNATURE-----

Merge tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull xen updates from Konrad Rzeszutek Wilk:
 "which has three neat features:

   - PV multiconsole support, so that there can be hvc1, hvc2, etc; This
     can be used in HVM and in PV mode.

   - P-state and C-state power management driver that uploads said power
     management data to the hypervisor.  It also inhibits cpufreq
     scaling drivers to load so that only the hypervisor can make power
     management decisions - fixing a weird perf bug.

     There is one thing in the Kconfig that you won't like: "default y
     if (X86_ACPI_CPUFREQ = y || X86_POWERNOW_K8 = y)" (note, that it
     all depends on CONFIG_XEN which depends on CONFIG_PARAVIRT which by
     default is off).  I've a fix to convert that boolean expression
     into "default m" which I am going to post after the cpufreq git
     pull - as the two patches to make this work depend on a fix in Dave
     Jones's tree.

   - Function Level Reset (FLR) support in the Xen PCI backend.

  Fixes:

   - Kconfig dependencies for Xen PV keyboard and video
   - Compile warnings and constify fixes
   - Change over to use percpu_xxx instead of this_cpu_xxx"

Fix up trivial conflicts in drivers/tty/hvc/hvc_xen.c due to changes to
a removed commit.

* tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen kconfig: relax INPUT_XEN_KBDDEV_FRONTEND deps
  xen/acpi-processor: C and P-state driver that uploads said data to hypervisor.
  xen: constify all instances of "struct attribute_group"
  xen/xenbus: ignore console/0
  hvc_xen: introduce HVC_XEN_FRONTEND
  hvc_xen: implement multiconsole support
  hvc_xen: support PV on HVM consoles
  xenbus: don't free other end details too early
  xen/enlighten: Expose MWAIT and MWAIT_LEAF if hypervisor OKs it.
  xen/setup/pm/acpi: Remove the call to boot_option_idle_override.
  xenbus: address compiler warnings
  xen: use this_cpu_xxx replace percpu_xxx funcs
  xen/pciback: Support pci_reset_function, aka FLR or D3 support.
  pci: Introduce __pci_reset_function_locked to be used when holding device_lock.
  xen: Utilize the restore_msi_irqs hook.
2012-03-22 20:16:14 -07:00

257 lines
6.7 KiB
C

/******************************************************************************
* Xen balloon driver - enables returning/claiming memory to/from Xen.
*
* Copyright (c) 2003, B Dragovic
* Copyright (c) 2003-2004, M Williamson, K Fraser
* Copyright (c) 2005 Dan M. Smith, IBM Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation; or, when distributed
* separately from the Linux kernel or incorporated into other
* software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/capability.h>
#include <xen/xen.h>
#include <xen/interface/xen.h>
#include <xen/balloon.h>
#include <xen/xenbus.h>
#include <xen/features.h>
#include <xen/page.h>
#define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10))
#define BALLOON_CLASS_NAME "xen_memory"
static struct device balloon_dev;
static int register_balloon(struct device *dev);
/* React to a change in the target key */
static void watch_target(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
unsigned long long new_target;
int err;
err = xenbus_scanf(XBT_NIL, "memory", "target", "%llu", &new_target);
if (err != 1) {
/* This is ok (for domain0 at least) - so just return */
return;
}
/* The given memory/target value is in KiB, so it needs converting to
* pages. PAGE_SHIFT converts bytes to pages, hence PAGE_SHIFT - 10.
*/
balloon_set_new_target(new_target >> (PAGE_SHIFT - 10));
}
static struct xenbus_watch target_watch = {
.node = "memory/target",
.callback = watch_target,
};
static int balloon_init_watcher(struct notifier_block *notifier,
unsigned long event,
void *data)
{
int err;
err = register_xenbus_watch(&target_watch);
if (err)
printk(KERN_ERR "Failed to set balloon watcher\n");
return NOTIFY_DONE;
}
static struct notifier_block xenstore_notifier = {
.notifier_call = balloon_init_watcher,
};
static int __init balloon_init(void)
{
if (!xen_domain())
return -ENODEV;
pr_info("xen-balloon: Initialising balloon driver.\n");
register_balloon(&balloon_dev);
register_xen_selfballooning(&balloon_dev);
register_xenstore_notifier(&xenstore_notifier);
return 0;
}
subsys_initcall(balloon_init);
static void balloon_exit(void)
{
/* XXX - release balloon here */
return;
}
module_exit(balloon_exit);
#define BALLOON_SHOW(name, format, args...) \
static ssize_t show_##name(struct device *dev, \
struct device_attribute *attr, \
char *buf) \
{ \
return sprintf(buf, format, ##args); \
} \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
BALLOON_SHOW(current_kb, "%lu\n", PAGES2KB(balloon_stats.current_pages));
BALLOON_SHOW(low_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_low));
BALLOON_SHOW(high_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_high));
static DEVICE_ULONG_ATTR(schedule_delay, 0444, balloon_stats.schedule_delay);
static DEVICE_ULONG_ATTR(max_schedule_delay, 0644, balloon_stats.max_schedule_delay);
static DEVICE_ULONG_ATTR(retry_count, 0444, balloon_stats.retry_count);
static DEVICE_ULONG_ATTR(max_retry_count, 0644, balloon_stats.max_retry_count);
static ssize_t show_target_kb(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%lu\n", PAGES2KB(balloon_stats.target_pages));
}
static ssize_t store_target_kb(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
char *endchar;
unsigned long long target_bytes;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
target_bytes = simple_strtoull(buf, &endchar, 0) * 1024;
balloon_set_new_target(target_bytes >> PAGE_SHIFT);
return count;
}
static DEVICE_ATTR(target_kb, S_IRUGO | S_IWUSR,
show_target_kb, store_target_kb);
static ssize_t show_target(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%llu\n",
(unsigned long long)balloon_stats.target_pages
<< PAGE_SHIFT);
}
static ssize_t store_target(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
char *endchar;
unsigned long long target_bytes;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
target_bytes = memparse(buf, &endchar);
balloon_set_new_target(target_bytes >> PAGE_SHIFT);
return count;
}
static DEVICE_ATTR(target, S_IRUGO | S_IWUSR,
show_target, store_target);
static struct device_attribute *balloon_attrs[] = {
&dev_attr_target_kb,
&dev_attr_target,
&dev_attr_schedule_delay.attr,
&dev_attr_max_schedule_delay.attr,
&dev_attr_retry_count.attr,
&dev_attr_max_retry_count.attr
};
static struct attribute *balloon_info_attrs[] = {
&dev_attr_current_kb.attr,
&dev_attr_low_kb.attr,
&dev_attr_high_kb.attr,
NULL
};
static const struct attribute_group balloon_info_group = {
.name = "info",
.attrs = balloon_info_attrs
};
static struct bus_type balloon_subsys = {
.name = BALLOON_CLASS_NAME,
.dev_name = BALLOON_CLASS_NAME,
};
static int register_balloon(struct device *dev)
{
int i, error;
error = subsys_system_register(&balloon_subsys, NULL);
if (error)
return error;
dev->id = 0;
dev->bus = &balloon_subsys;
error = device_register(dev);
if (error) {
bus_unregister(&balloon_subsys);
return error;
}
for (i = 0; i < ARRAY_SIZE(balloon_attrs); i++) {
error = device_create_file(dev, balloon_attrs[i]);
if (error)
goto fail;
}
error = sysfs_create_group(&dev->kobj, &balloon_info_group);
if (error)
goto fail;
return 0;
fail:
while (--i >= 0)
device_remove_file(dev, balloon_attrs[i]);
device_unregister(dev);
bus_unregister(&balloon_subsys);
return error;
}
MODULE_LICENSE("GPL");